The Duke of Sussex will fly to the UK later this month for the ceremony in the grounds of Kensington Palace.
The tribute will take place on July 1, on what would have been Diana’s 60th birthday, but Harry will need to self-isolate for at least five days beforehand.
According to The Sun, Charles will be in Scotland when Harry arrives and there is currently no planned meeting between father and son.
A source said: “Charles will leave the boys to it. Harry will need to quarantine for at least five days when he lands in England, most likely at Frogmore Cottage in Windsor.
“Charles has made it quite clear he will not be around beyond that because he is going to Scotland. There is no planned meeting between the three of them.”
Prince Harry told Oprah Winfrey that his father had stopped taking his calls in a candid interview in March.
Harry and his wife Meghan Markle stepped down from their roles as senior royals last year.
They now live in California with their son Archie, two, and two-week-old daughter Lilibet.
Prince Harry and his brother Prince William are said to be embroiled in a bitter family feud but will put on a united front at the statue unveiling next month.
A source said: “The boys will walk out together out of respect for their mum.”
They will also deliver their own speeches at the poignant event.